New technological advances in measurement and data acquisition have generated massive data streams. Translating this information into new knowledge, and improved patient care and outcomes, is proving difficult. This is particularly relevant in critical illness. Mathematical theory and models are emerging as central tools of discovery in Systems Biology, the emerging transdisciplinary science that proposes an integrative framework of interpretation of these data. A key barrier to the widespread implementation of complex modeling in acute illness is the gulf separating clinicians and bench researchers on the one hand, and modelers on the other. Further skepticism as to the utility of this integrated approach exists in large segments of academia entrenched in a epistemological paradigm of reductionism that, although time tested, may well prove insufficient to elucidate complex non-linear reality. To improve collaboration and dialog among these groups, we founded the Society for Complexity in Acute Illness (SCAI, www.scai-med.org) and a yearly conference entitled "International Conference on Complexity in Acute Illness" (ICCAI, www.iccai.org). The goals of this conference are to 1) facilitate open exchange among clinicians, biological scientists, and modelers, 2) present original research in complex modeling relevant to acute illness, 3) provide a forum for young and underrepresented scientists to present and learn from interdisciplinary research, 4) standardize modeling efforts in human disease, and 5) promote scientific diffusion of these efforts by the publication of manuscripts in suitable scientific journals. We request support for the next four installments of the ICCAI (2006- 2009). ICCAI, now the annual meeting of SCAI, will next be held in Washington, DC, on October 19-21, 2006. These funds will be targeted to facilitating the participation of young and promising scientists to ICCAI. We are building on the experience of four prior annual conferences. Themes to be covered in 2006 include: 1) systems biology and critical illness - defining the challenges, 2)modeling inflammation and damage, 3)multi-scale approaches to organ function and dysfunction, 4)physiological control: theory and practice, 5)resource generation and sharing and 6)complexity and translational research. Each thematic session, under the direction of a chair and co-chair, includes formal presentations by established scientists, followed by questions and discussion. We put a strong emphasis on poster and oral presentations by young researchers. Scientific abstracts will be solicited and meritorious ones selected for presentations, and published in the December 2006 issue of the Journal of Critical Care.